Such electrophoresis methods and apparatuses are known from the U.S. Pat. Nos. 4,148,703 and 4,473,452. According to these two patents two electrode pairs are used, which are put under voltage alternately, and which are so located relative to the separation medium that the generated electric fields drive the particles to be separated alternately in different directions in the separation medium.
Besides two electrode pairs, a switching device is also required in such apparatuses to alternately put the electrode pairs under voltage. Such apparatuses are comparatively expensive.
Moreover, with electrodes on four sides of the separation medium the mutual positioning of the electrodes will be critical.
It should also be pointed out that no good separation will be obtained when the electrodes are located in such a manner that the electric fields generated by the respective electrode pairs are perpendicular to each other.